Numerical investigation of conjugate heat transfer to a turbulent dual offset jet

Abstract

The present study considers a computational model to simulate conjugate heat transfer to a turbulent dual offset jet from a heated wall having a finite thickness and subjected to a constant wall temperature. To capture the effects of turbulence on the flow and heat transfer, the Reynolds Averaged Navier–Stokes equations (RANS) with the standard k−ε turbulence model have been employed. The convection equation in the flow regime is solved together with the conduction equation in the solid medium iteratively. For the purpose of the analysis, four parameters, namely, the Reynolds number (Re), the thermal conductivity ratio of the solid material and the fluid, the solid wall thickness, and the fluid Prandtl number (Pr), are varied within suitable ranges. The flow field solution exhibits two recirculation zones; the first one is enclosed by the two jets and the other is formed underneath the lower jet. Conjugate heat transfer to the dual offset jet flow is analysed through the distribution of temperature, heat flux, and Nusselt number, at the interface between the fluid and solid regions. Results indicate that the non-dimensional temperature and heat flux profiles along the fluid–solid interface depend on all four parameters. In contrast, the distribution of the Nusselt number along the fluid–solid interface depends only on the Reynolds number and the Prandtl number. Increasing either of them leads to an overall increase in the interface Nusselt number. A correlation for the average Nusselt number along the interface is presented as a function of Re and Pr.